In a series and parallel combined electric vehicle (SPHV) disclosed in JP-3052753-B, when the revolution speed of a motor decreases to be lower than a predetermined value while the vehicle is running in a parallel hybrid vehicle (PHV) mode, a mechanical connection between a generator and the motor is released by releasing a clutch, whereby the vehicle is shifted to a series hybrid vehicle (SHV) mode. When the vehicle is running in the PHV mode, the wheels are driven by mechanical output from an engine, and when the vehicle is started, accelerated or slowed or stopped using brakes, a difference between a required output and the mechanical output of the engine is made up for by the motor. Additionally, when the vehicle is running in the SHV mode, the generator is driven by the mechanical output from the engine, and the motor is driven by electric power generated by the generator and electric power discharged from a battery, whereby the wheels are driven by the motor.